package main
import "fmt"
import "Strings"
func main() {
	var str = "hello world"
	fmt.Println(str)
	fmt.Println(strings.ToUpper(str))
	fmt.Println(strings.ToLower(str))
	fmt.Println(strings.Replace(str,"hello","hi",1))
	fmt.Println(strings.Split(str," "))
	fmt.Println(strings.Join([]string{"hello","world"}," "))
}